Although he's a bookworm, he's a very kind person.
Tips
usage
书呆子 is mildly derogatory, implying someone is smart with books but socially awkward or impractical. It's similar to English 'bookworm' or 'nerd' but with more emphasis on lacking real-world skills.
culture
In Chinese culture, studying is highly valued, but being a 书呆子 is seen as going too far - knowing only theory without understanding how the world works. The ideal is 学以致用 (study for practical application).
